Most of now available rubber seal materials suffer from sticking problems between seal materials themselves or sticking to contact surfaces of mating materials such as metals, resins, etc., when assembled into equipment. To overcome such problems, a liquid material such as wax, grease, lubricating oil, etc. is applied to the seal materials, thereby improving the assembling work.
When rubber parts such as O rings, etc. are transported by a parts feeder to conduct automatic assembling, the more the liquid material is applied, the lower the friction coefficient, but blocking of the parts themselves will occur due to sticking of the applied liquid material, thereby bringing about an inconvenience to the automatic feeding of the parts. To reduce the sticking occurrence, on the other hand, the less the liquid material to be applied, the more often the liquid material is liable to deposit onto the surroundings, thereby causing the blocking. The applied liquid material is liable to come off due to the liquid nature, and thus its retainability is not sufficient. Furthermore, it is difficult to control the application amount of the liquid material, and thus it is difficult to obtain the rubber parts in a stable state only by the liquid material. Blocking as well as sticking can be prevented by spraying inorganic powders of graphite, silica, talc, etc., but surrounding pollution due to disengagement of the deposited powders is inevitable.
To overcome such problems, Patent Document 1 proposed a surface-treating agent, which comprises (1) a reaction product of polysiloxane having a terminal hydroxyl group, with silyl isocyanate, (2) a reaction product of an oligomer having a functional group reactive with an isocyanate group, with silyl isocyanate, (3) a silyl isocyanate oligomer represented by the following general formula:
(R: an alkyl group, an aryl group, or an isocyanate group, and n: an integer of 1 or more), and (4) an organic solvent-soluble rubber. The assembling work and stickiness can be improved by such a surface-treating agent, but the major component of the surface-treating agent is an organic solvent such as toluene, ethyl acetate, methyl ethyl ketone, etc., which can also lead to such problems as a high environmental load and a difficult handling.
Patent Document 1: JP-A-2000-63744
Patent Document 2 proposes an aqueous mold-releasing agent composition for use upon application to the surface of a mold, which comprises (A) a silicone emulsion, (B) a urethane resin-based aqueous emulsion, and (C) a silane compound having at least one of epoxy group and methacryloxypropyl group at the molecular chain terminal, and/or a partial hydrolyzate thereof. Such a composition has a low environmental load due to the aqueous system, but has a problem of surrounding pollution due to bleeding of oily matters onto the surface after application and drying, when used as a surface-treating agent for the sliding members, which is the object of the present invention, because the aqueous emulsion containing a polyhydrazide and a carbonyl group-containing polyurethane•vinyl•hybrid polymer is used as Component (B). Furthermore, tight adhesion to the rubber materials is not satisfactory, resulting in short durability and easy peeling. Thus, the proposed composition is not preferable.
Patent Document 2 JP-A-2005-125656